* spawn.cc (spawn_guts): Close handle `hToken' only if it's not

copied from myself->token.
        * syscalls.cc (seteuid): Replace CopySid by memcpy which is foolproof
        here.

winsup/cygwin/spawn.cc

@@ -640,7 +640,7 @@ skip_arg_parsing:
   ResumeThread (pi.hThread);
   ForceCloseHandle (pi.hThread);
 
-  if (hToken)
+  if (hToken && hToken != myself->token)
     CloseHandle (hToken);
 
   DWORD res;